Trigger mechanism for cartridge tool

ABSTRACT

A gun for driving nails, bolts, etc., by force generated by detonating an explosive cartridge, includes a firing mechanism with a striker pin for detonating the cartridge by operating the firing mechanism. The gun comprises a trigger mechanism with a transversally disposed spring-actuated blocking member with occupies one axial position when the safety of the gun is off and another axial position when the safety is on. There is further provided a two-arm pivotal lever. One end of this lever serves to displace the blocking member inwardly when said member is in the one axial position and the other end of the lever enters into a transverse hole in a trigger which is axially movable and under pressure by a spring. The other lever end is connected to the trigger so that a rearward movement of the trigger against the pressure acting thereupon causes said one end of the lever to be displaced forwardly in the longitudinal direction of the nail or other element to be fired from the gun. The lower side of the lever is designed for coaction with the opposite side of the hole in the trigger so that upon forward movement of the trigger, the opposite surfaces impart to the respective ends of the lever a movement out of the longitudinal axis of the nail or other element by firing by the gun.

United States Patent [191 Larsson June 18, 1974 1 1 TRIGGER MECHANISMFOR CARTRIDGE TOOL [75] Inventor: Sven Gunnar 010i Larsson,

Huskvarna, Sweden [73] Assignee: Gunnabo Bruks Aktiengesellschaft,

Huskvarna, Sweden [22] Filed: Jan. 30, 1973 [21 1 Appl. No.: 327,922

Primary Examiner-Benjamin A. Borchelt Assistant ExaminerC. T. JordanAttorney, Agent, or FirmHane, Baxley & Spiecens [57] ABSTRACT A gun fordriving nails, bolts, etc., by force generated by detonating anexplosive cartridge, includes a firing mechanism with a striker pin fordetonating the car tridge by operating the firing mechanism. The guncomprises a trigger mechanism with a transversally disposedspring-actuated blocking member with occupies one axial position whenthe safety of the gun is off and another axial position. when the safetyis on. There is further provided a two-arm pivotal lever. One end ofthis lever serves to displace the blocking member inwardly when saidmember is in the one axial position and the other end of the leverenters into a transverse hole in a trigger which is axially movable andunder pressure by a spring. The other lever end is connected to thetrigger so that a rearward movement of the trigger against the pressureacting thereupon causes said one end of the lever to be displacedforwardly in the longitudinal direction of the nail or other element tobe fired from the gun. The lower side of the lever is designed forcoaction with the opposite side of the hole in the trigger so that uponforward movement of the trigger, the opposite surfaces impart to therespective ends of the lever a movement out of the longitudinal axis ofthe nail or other element by firing by the gun.

3 Claims, 21 Drawing Figures I. A26 l 26' s 42 i T a f8 $3 1 23 47 lZEPATENTEUJM 18 m4 SHEET K [If 6 9% m MN m w The present invention relatesto a trigger mechanism for a cartridge tool, which contains a releasingmechanism which has a transversally arranged springactuated blockingmember which blocks the movement of a spring actuated striker pin, andwhen the blocking device is displaced inwards the blocking of thestriker pin ceases, and the striker pin initiates the cartridge when thecartridge tool is loaded. Owing to safety factors, the spring whichactuates the blocking member must bevery powerful which involves thatgreat force is required in order to move the blocking device inwards. Atthe same time, it is desired that the trigger, which is actuated by ahuman finger, need not be subjected to great force in order to displacesaid blocking member.

The purpose of the present invention is to solve the displacementinwards of the blocking member when the blocking member in theoff-safety position is located substantially behind the trigger, and theforce on the trigger is then to be little in relation to the force atthe blocking member. According to the invention, this is achieved by atwo armed lever being arranged in the cartridge tool, which is supportedbetween its end points in the actual cartridge tool. The rear end of thelever coacts with the blocking member, while the front end is pivotablyconnected with an arm which is inserted in a transversal hole in anaxially movable trigger which is subjected to spring actuation or thelike. The other end of the arm is supported at the trigger in such a waythat when the trigger is moved rearwards the blocking member isdisplaced inwards. Further, on its under side, the two-armed lever has asurface coacting with an opposite surface in the hole in the trigger, sothat at a forwards movement of the trigger the rear end of the leverwill cease to function together with the blocking member.

The end of the lever which coacts with the blocking member has anobliquely chamfered surface which coacts with an obliquely chamferedsurface on the blocking member, so that if the cartridge tool isactuated accidentally, the two oblique surfaces will come into contactwith each other, so that accidental firing is prevented.

Further characteristic properties of the invention will be noted fromthe following claims.

In the following, a complete cartridge tool containing the presentinvention will be described, with reference to the attached drawings,

FIG. 1 shows a complete cartridge tool,

FIG. 2 shows where in said cartridge tool a cartridge case ejector isarranged,

FIGS. 3 and 4 show two illustrations demonstrating the cartridge caseejector in two different functioning positions,

FIGS. 5 and 6 show a snap arrangement for fixing a nail with guidewasher in two different functioning positions,

FIGS. 7, 8 and 9 show a muzzle part with the surrounding sleeve of thecartridge tool,

FIGS. 10 and 11 show the front end of the cartridge tool,

FIGS. 12 and 13 show a cartridge chamber with a cartridge for the toolbefore and after the cartridge has been fired,

FIGS. 14 and 15 show the trigger mechanism in two different functioningpositions,

FIGS. 16 and 17 show the coaction between a guide pin engaging in agroove in the barrel of the cartridge tool and the groove in twodifferent relative positions,

FIGS. 18, 19 and 20 more completely show the coaction between the pinaccording to FIGS. 16 and 17 and a striker piston in three differentrelative positions, and

FIG. 21 shows how said pin is actuated transversally.

In FIGS. 1 and 2 the reference designation 1 shows a tool body sectionmade in one piece of metal. This part has a handle part 2 and from thehandle part there is a part 3 directed axially forwards, at the top ofwhich there is a guide part 4 with a more or less cylindrical hole forguiding a barrel 68, so that this can move axially along the hole. Tothe right of the handle part 2 a housing 6 is arranged for a triggermechanism 7. The housing is provided with an axial hole. which iscoaxial with the hole in the part 4. The part 8 between the guide part 4and the housing 6 has the character of a cradle. A cross-section of thecradle shows that it has a semi-circular form and that the innerenvelope surface of the cradle forms a joining envelope surface be tweenthe inner envelope surface of the guide part 4 and the inner envelopesurface of the housing 6. In the guide part 4, the part 8 and thehousing 6 a tubular cylinder lining 9 is arranged, which is cut away atthe part 8 so that within the part 8 a cradle-like lining is formed. Atits front end the cylinder lining has a radial flange 10, directedoutwards. The rear end of the cylinder lining protrudes outside thehousing 6. The protruding part is provided with external threads 11. Acasing 12 with internal threads 13 is screwed on to the threads 11. Thehandle part 2, at its rear end, is provided with a coherent member 14which can be made of, for instance, some elastic material, such asrubber or plastic. The member 14 has such an extent that it also coversthe casing 12 and part of the outer surface of the housing 6. Theelastic material has the function of absorbing part of the recoil force.The coherent member 14, of elastic material, is secured to the handlepart 2 with the aid of a threaded screw 15.

The firing mechanism consists of a cylindrical unit 16. The cylindricalunit 16 has a transversal hole 17. A bolt 18 is inserted in the hole 17.Between the inner end of the bolt and the bottom of the hole a spring 19is arranged. The bolt 18 has a transverse hole 20, in which is insertedthe front end of a striker pin member 21. At the top of the hole thereis a catch for the striker pin member 21, which is put out of functionwhen the bolt 18 moves rearwards. At its front end the striker pinmember 21 has a striker pin 22. The left side of the hole 20 isdelimited by a wall 23, provided with a hole 24, of appropriate size sothat the striker pin 22 can be placed in the hole with a small portionprotruding outside the left side of the wall 23. At its lower end thebolt 18 has a lug 25, which slides in an axial groove 26 in the cylinderlining 9. In this way the cylindrical unit 16, because of the lug 25,can move in the lining 9 only in the longitudinal direction of thegroove 26, between the end positions of this. The cylindrical unit 16has a part of it recessed so that a transversal contact surface 27 isformed. The recessed part has the character of a cylinder, and has beengiven the reference designation 28. One end of a helical spring 29 bearsagainst the contact surface 27. The other end of the spring bearsagainst the transversal flange 30 of a member which forms said flange,and a tubular part 31. The tubular part 31 has a contact surface 32. Thetubular part 31 forms a passage for the striker pin member 21, and atits rear end the striker pin member has a flange 33, which can bebrought to bear against said contact surface 32. The striker pin member21 is provided with a spring 34, one end of which bears against the leftend of the striker pin member 21, and the other end against the innerwall of the casing 12. The tubular part 31 is encircled by three rings35, 36 and 37, which bear against the transversal flange 30 and thebottom of the casing 12. These three rings are of elastic material, andare capable of absorbing recoil forces.

At the upper end of the handle 2, an axial, more or less rectangularthrough hole 38 is arranged. The hole 38 emerges into a conventionaltrigger opening 39. The axial groove 26 emerges at the upper part of thethrough hole 38. In the groove a two-armed lever 41 is arranged, (seeFIGS. 14 and one end 40 of which can move in the groove 26, so that alug 42 arranged at the top of said one end 40 can coact with the lug ofthe bolt 18. The two-armed lever 41 is arranged so that it can pivotaround an axle 43, which is arranged in the handle part 2. The other end44 of the two-armed lever 41, via an axle 45 has a two-armed arm 46supported on it, with one arm 47 directed more or less downwards and anarm 48 which is more or less horizontal. The horizontal arm 48 isarranged in an axial groove 49 running through the two-armed lever 41.The arm 47 which is directed downwards has an oval groove 50. Throughthe hole there is a pin 51. The pin is arranged in a trigger 52. Thetrigger is movable axially in the through hole 38, and has a more orless vertical hole 53 for the arm 47 which is directed downwards. At itsrear end the trigger 53 has a hole 54, which extends more or lessaxially. One end of a helical spring 55 bears against the bottom of thehole 54 and the other end of the spring bears against the bottom of ahole 56, arranged in the coherent member 14. The helical spring causesthe trigger to be always in its front position, at the same time as thetwo-armed lever 41 is caused to be in its lower position.

In thecylindrical unit, as will be noted from FIG. 2, a groove 57 hasbeen cut down from the envelope surface, which groove has an axialdirection, so that an arm 58 can be placed in the groove 57. From theends of the arm 58, two arms 59 and 60 extend, as will be noted fromFIGS. 3 and 4. The last-mentioned two arms have a transversal directionin relation to the arm 58 and are moreover substantially directedtowards the centre axis of the cylindrical unit 16. At its front end,the arm 60 is shaped into a point 61, intended to coact with a flange 62of a cartridge case 63. At the upper end of the arm 59 a cut-downsection 64 has been made. Part of one end of the helical spring 29 restsagainst said cut-down section. The arm 59 penetrates into a groove 65made in the striker pin member 21. The arm 59 is made with a point 66,which point is in contact with the front cross wall 67 of the groove 65,so that the helical spring 29 will impart a moment directed forwards tothe arm 58, so that the point 61 can snap in, in front of the front sideof the flange 62.

A barrel 68 is arranged so that it can be displaced axially in thecylindrical lining 9 (see FIG. 1). At its rear end the barrel has achamber 69, the front end of which emerges into a bore 70 of the barrel.At its front end the barrel 68 has internal threads 71, which coact withexternal threads 72 of a muzzle part 73, which has a bore 74 with adiameter substantially corresponding to the head 100 of a nail 99. Atits front end the muzzle part 73 has a diameter junction, so that a bore75 with a greater diameter is obtained, i.e., a diameter correspondingto the diameter of a guide washer 101 for the nail 99 see FIGS. 5 and6). In the bore 70 a striker piston is arranged, which has a rear part76 with a diameter corresponding to the diameter 70 of the bore and afront part 77 which is always inserted in the bore 74, which part 77 hasa diameter corresponding to the bore 74. The barrel 68 has a throughaxial groove 78 arranged in a vertical plane through the barrel 68. Inthe groove a spring actuated lug 79 (see FIGS. 1 and 18) is inserted,which limits the movement of the barrel 68 towards the left so that thelug 79 in one position can be in contact with the rear end wall 80 ofthe groove 78. In this position the rear end of the barrel 68 mainlycoincides with the rear end of the guide part 4. The lug 79 moreover isinserted so far into the bore 70 that it can be made to come intocontact with the more or less transversal bearing surface 81 of the rearpart 76. In the front end of the bore 70 and in front of the lug 79 aring 82 of elastic material is arranged, and in front of this and incontact with the rear end of the ring there is a flange-like part 83 ofa tubular part 84. The tubular part 84 has a groove 85 for the lug 79.The barrel 68 has a step on its underneath side at the groove 78, sothat when the lug is completely inserted in the barrel 68, this can moverearwards but not forwards.

In the part which is directed forwards straight under the groove 78 inthe barrel 68 an axial groove 86 is arranged, which emerges into apocket 87. Above the groove 86 the lining 9 is provided with a throughgroove 86A, for which a number of through holes can be substituted. Thepocket 87 is intended to be covered with a side cover or the like which,for instance, is fastened to the pivot 88. The pocket is also shown inFIGS. 10 and 11. The lining 9 has a peripheral bead 89, which has a moreor less rectangular cross section. Between the outer envelope surface tothe left of the peripheral bead a ring-formed space 90 is arranged,which is limited by the inner envelope surface of the guide part 4.Around its outer envelope surface the lining has longitudinallyextending axial ribs 91, originating from a point on the lining locatedbetween the ends 4 of the guide part. The axial ribs extend up to thefront end of the guide part 4. The upper sides of the axial ribs are incontact with the inner envelope surface of the guide part 4. In this waythe lining in the guide part 4 obtains a number of axial channels aroundits periphery in which the exhaust gases of the bolt gun aredistributed. As the flange 10 is at a certain distance from the frontend of the guide part 4, an exhaust opening 92 for said channels isobtained. A space corresponding to the space 90 can be arranged betweenthe front edge of the ribs 91 and said exhaust opening.

The muzzle part 73 has a relatively shallow peripheral recess 93, asshown in FIGS. 5 and 6. In the left part of the muzzle part, which isnot recessed, there is an axial, shallow groove 94, which extends to theleft from the recess 93. In the front end of this groove, i.e. at itsleft end, there is a radial hole 95, in which a ball 96 is placed. Thelower end of the hole is slightly constricted, so that the ball cannotleave the hole 95 and become lodged in the bore part 75. Around themuzzle part 73 and then at the recess 93 a peripheral band 97 is placed.From one edge of the band a tongue 98 extends to the left along theaxial groove 94. The tongue then covers the hole 95, so that the ballcannot be dislodged upwards. The band 97 and the tongue 98 are of suchmaterial that the tongue always strives to press the ball 96 downwards.The function of the ball 96 is to snap aside at the insertion of a nail99 with a nail head 100 and a guide washer 101 into the bores 74 and 75which are arranged one after the other. When the ball has snapped aside,the nail 99 is retained in the bore. The advantage of this designcompared with other designs is that the recess in the front part of themuzzle part 73 will be considerably smaller, which gives the front partgreater strength. When other designs are used for retaining the ball 96,substantially greater recesses have had to be made. The arrangementdescribed for retaining the ball 96 can of course be applied generallyat muzzle parts for any arbitrary bolt guns whatsoever.

The muzzle part 73 is encircled by a collar 102 consisting of a frontpart 103 and a rear part 104, which is also shown in FIGS. 7 9. The rearend 104 is intended to have its edge in contact with the flange 10. Acertain portion of the front part of the muzzle part 73 then protrudesout in front of the front edge of the part 103. In order to release thesafety of the bolt gun, the front end of the muzzle part must be pressedin to such an extent that its front part coincides with the front edgeof the part 103.-On its inner envelope surface the part 104 has tworadial flanges 105 and 106, directed inwards. These flanges have twosurfaces facing each other, which are parallel with each other. A crosssection through the flanges gives an internal hole with two straightparallel sides and two curved sides facing each other. On the muzzlepart 73, there is a dice-shaped part 107 which forms a peripheral raisedsection in front of the external threads 72. The dice-shaped part 107has four axial flat surfaces 108, 109, 110 and 111. The surfaces 108 and110 are at a distance from each other which mainly corresponds to thedistance between the inner edges of the flange parts 105 and 106. Thedistance between the surfaces 109 and 111 is the same. At the left endof the surfaces 111 and 109, two curved flanges 112 and 113 arearranged, the curvature then approximately corresponding to the internaldiameter of the part 104. When the muzzle part 73 is inserted into thecollar 102, the flanges 112 and 113 must obtain the position shown inFIG. 8. When the flanges 112 and 113 have passed the flanges 105 and106, and the diceshaped part 107 is to the left of the flanges 105 and106 which are directed downwards, they can be turned 90. Thereafter themuzzle part 73 can be moved from contact through the flanges 112 and 113against the flanges 105 and 106 to contact with the contact surface 114.Due to the existence of the flanges 105 and 106 and the surfaces 108 to111 it is possible with the aid of the collar 102 to screw on the muzzlepart 73 to the barrel 68. The collar 102 thus has three functions, viz.to serve as a cover, to serve as a member which determines how far thebarrel 68 should be moved rearwards in order that the safety device ofthe bolt guns shall be released, and to serve as a member with the aidof which the muzzle part 73 can be unscrewed from or screwed on thebarrel 68. The collar cannot move the bolt gun or release the safety. Inits rearmost position the collar leaves part of the front end of themuzzle part 73 uncovered. However, this part is not sufficient toprovide a grip for a user. The collar 102 described can of course have:applications also on bolt guns of types other than the present one.

At the rear end of the barrel 68 a cylindrical hole 1 15 is arranged forthe flange 62 of a cartridge 63 with a cylindrical main body 117 and afront more or less conical and folded part 118. (see FIGS. 12 and 13).The main body 117 is placed in a cylindrical hole 119 which has adiameter mainly corresponding to the diameter of the cylindrical mainbody 117. The cylindrical hole 119 is followed to the left by a conicalhole 120 with an inner edge 116. The conical hole 120 thereafter goesover into a hole 121 for transmission of the powder gases developed fromthe cartridge when this has been initated. The taper of the conical holeand the length of the cylindrical hole have been chosen in such a waythat when the cartridge has been initiated the front edge 122 of theconical hole will function as a breaking edge, which involves that thefolded front part 118 will be transformed into a conical part 123 and atubular part 124. In this way, the front part of the cartridge will notbecome jammed in the chamber, nor will any residue be deposited in thechamber 69, which can make the chamber tighter and thereby causecartridges subsequently loaded to be jammed in the chamber. At thechamber 69 the barrel 68 has an axial groove, which is radial, so thatthe arm 60 can obtain the contact shown in FIG. 4. The design describedof the cartridge chamber is not limited for use in the present type ofbolt gun, but can have general application.

The previously described trigger mechanism has been described to arather great extent, but not sufficiently, however, and therefore, inthe following, the trigger mechanism will be described in more detail.(see FIGS. 14 and 15). The horizontal arm 48 can move in an axial groove49 in the two-armed lever 41 and its free end can be caused to come intocontact with the outer envelope surface of the casing 9. The appearanceof the groove will perhaps best be noted from FIG. 2. The lug 25 for thebolt 18 has two oblique sur faces, which are transversal, and have thereference designations 125 and 126. The inclination of the surfaces ismax. 80". In the longitudinal section the lug 25 has a dove-tailcharacter. The lug 42 has an oblique front side surface 127 with aninclination of 80, for coaction with the side surface 126 of the lug 25.The other end 44 of the lever 41 has an oblique contact surface 128 forcoaction with an oblique or chamfered surface 129 in the upper left-handside of the through hole 53. When the trigger 52 is moved towards theleft, the oblique contact surface 128 is caused to slide along thechamfer 129, which involves that the part 44 of the two-armed lever 41obtains a movement upwards, at the same time as the end 40 of the leverobtains a movement downwards.

FIG. 16 shows the front part of the barrel 68 and also its axial groove78 and the inserted lug 79. The lug 79 has a more or less rectangularcross section, and a width mainly corresponding to the width of thegroove. Outside the groove 78 the lug changes over into a part 130 whichcannot enter into the groove 78. The part 130 can appropriately be givena cylindrical form. and in the barrel 68 two recesses 131 and 132 havebeen made on either side of the groove 78, and then in the outerenvelope surface of the barrel. The purpose of this is to achieve aguide groove for the part 130. The part 130 thus fits in the grooveformed by the recesses 131 and 132. At its left end the groove formedhas an inclined cross wall 134, which involves that the part 130, whenmoving towards the left, can slide upwards on the inclined wall 134 andcan be caused to come into direct contact with the outer envelopesurface of the barrel. The groove formed by the recesses 131 and 132 hasa cross wall 133 to the right, which is at right angles to the axis ofthe barrel 68. This involves that when the part 130 moves to he right,the part is caused to come into contact with the cross wall 133, and hasno possibility of sliding up on the envelope surface of the barrel. Thecontact of the part 130 against the cross wall 133 will be noted fromFIG. 17. FIG. 18 shows how the part 130' is movably arranged in thetransversal direction in a lining 135, which is arranged in part 3, in ahole. The lining 135 is screwed into a hole in the tubular lining 9. Atits bottom the lining 135 has an end wall 136. At the bottom, the part130 changes over into a more or less cylindrical journal formed part137, which passes through a hole 138 in the end wall 136. The journalformed part 137 has its lower end supported in a transversal grip part139, and then by means of a shaft 140, which goes through thetransversal grip part 139 and the journal formed part 137. Thetransversal grip part has two grip surfaces 141 and 142, which will belocated on either side of the bolt gun, as shown in FIG. 1. The grippart 139 is in contact with the outer side of the end wall 136. If oneof the grip surfaces 141 and 142, for instance the grip surface 142, isactuated by a finger 143 (see FIG. 21) the part 130 will be caused tomove downwards so far that the part 130 will leave the groove formed bythe recesses 131 and 132, i.e., the barrel 68 has the possibility ofmoving forwards until the lug 79 comes into contact with the end wall 80of the groove 78. At said actuation, the portion of the grip part to theleft of the shaft 140 will function as a pivot for a lever formed by thegrip part 139. The purpose of the spring 144 is to return the part 130to its original position.

The ring of elastic material 82 and the tubular part 84 serve thepurpose of braking up the forwards movement of the striker bolt 77, asthe contact surface 81 comes into contact with the right end edge of thetubular part 84 (see FIG. The tubular part 84 also serves the purpose ofprotecting the lug 79 from being destroyed through the rear part 76. Theparts 82 and 84 can be used generally in bolt guns.

The bolt gun described above functions in the following way. It isassumed that through a depression of the transversal grip part 139 thebarrel has had the possibility of moving so far to the left that the lug79 is in contact with the end wall 80. In this situation the strikerbolt 77 assumes its rear position in the bore 70. A cartridge 63 is nowinserted in the chamber 69. The barrel 68 is thereafter moved towardsthe right end until the part 130 comes into contact with the end wall133, as is clearly shown in FIGS. 17 and 18. A nail 99 with a nail head100 and with a guide washer 101 is inserted in the bores 74 and 75. Inorder that the nail with guide washer shall remain in place in the bores74 and 75 the guide washer for the nail must pass by a locking ball 96,which is actuated by a tongue 98, so that part of the ball penetratesinto the bore 75 The tongue 98 is spring actuated. When the nail isinserted in the bores 74 and 75,

the ball 96 is caused to snap aside, against the spring actuation, whenthe guide washer passes by. When the guide washer has passed, the ballagain falls down and blocks the movement of the guide washer towards theleft. The nail is thereby retained in the bore, and is ready to befired. It should be obvious that the nail can be inserted first andthereafter the cartridge.

In the situation described the barrel assumes such a position that theoblique surface 126 of the lug 25 is located in front of the obliquesurface 127 of the lug 42. Thus, firing cannot take place. If the collar104 has its rear end in contact with the flange 10, the muzzle part 74is protruding so far from the front end of the collar as is required toposition the lug 25 directly under the lug 42. If the front end of themuzzle part 73 is now pressed against the surface into which a nail isto be driven, against the action of the helical springs 29 and 34, thebarrel 68 will move rearwards so that the left end surface 103 of thecollar 102 will be caused to coincide with the left end surface of themuzzle part. the bolt gun is now ready to be fired, i.e. the lug 42 islocated directly under the lug 25. When firing, the trigger 52 is movedto the left, against the action of the spring 55. The journal 51 of thetrigger then moves the arm 47, which involves that the arm 47 pulls downthe left part 44 of the lever 41, which involves that the righthand part40 presses up the bolt 18 so far that the striker pin member 21 isreleased for a movement towards the left, and the striker pin 22 passesthrough the hole 24 and sets off the cartridge 63. Due to the leversystem, very little force is required on the trigger 52 in order to movethe bolt 18 which, for safety reasons, is actuated by a very powerfulspring. When the firing has taken place, the spring 55 presses thetrigger 52 towards the left. At this movement the oblique contactsurface 128 will slide along the chamfered surface 129, which involvesthat the lever 41 is turned clockwise, so that the lug 42 ceases tocoact with the lug 25. The trigger 52 with the arms is now ready for anew firing. At the initiation of the cartridge 63 the striker bolt 76and its front part 77 will more towards the left, to drive in the nail99 with the part 77. At the movement of the striker bolt towards theleft, the bolt is caught up by the contact surface 81 at the right endof the tubular part 84. Because of the elastic ring 82, the bolt 76 iscaught up gently. The exhaust gases from the cartridge 63 pass throughthe groove 78 and the groove 86A underneath in the lining 9 and thegroove 86 in the part 3 to the pocket 87, where the gases make aloop-formed movement downwards and thereafter pass up to the left of theperipheral bead 89, after which they are given an axial directionforwards in the space between the outer envelope surface of the lining 9and the inner envelope surface of the guide part 4. Owing to theexistence of the axial ribs, the gases are distributed out into a numberof channels, which emerge into the space 92 and thereafter out into theopen air. Due to the passage through the channels, the part jets arephase shifted in relation to each other. When the gases pass through thepocket 87, the powder residue is left in the pocket. This residue can beremoved from the bolt gun when the cover on the pocket is removed. Bydistributing the gases to a number of channels, which are formed by theribs, a silencing effect is obtained. Both the residue collecting pocketand the silencer can each be applied generally in bolt guns.

When the cartridge 63 is fired, a recoil occurs. Its effect is dampenedby the member 14, which is of elastic material. The recoil is furtherdampened by the three rings 35, 36 and 37, which are of elasticmaterial.

When the nail has been driven in, the transversal grip part 139 is givena downward movement through a finger 143 through actuation downwards oneither of the grip surfaces 141 or 142, and the cylindrical part 130 isthen caused to leave the groove formed by the recesses 131 and 132. Thebarrel 68 can then be moved towards the left, all the way to coming intocontact with the end wall 80. This movement of the barrel towards theleft can be obtained either by allowing the barrel to fall down of itsown weight, or by giving the barrel a centrifugal force. The barrel canalso be pulled out. At the movement of the barrel towards the left, thestriker piston is retained in a stationary position in the bolt gun tothe lug 7. This involves that during the movement of the barrel towardsthe left a relative displacement between the striker piston and thebarrel takes place, so that the striker piston with its bolt will bereturned to its original position. When this has taken place, the boltgun is loaded anew with cartridge and nail, and the barrel is returnedto the position where the barrel and nail are ready for driving a newnail.

As previously mentioned, the purpose of the collar 104 is to protect themuzzle part 73 as well as to regulate the length of the distance whichthe barrel must be pushed rearwards in order to release the safety ofthe bolt gun. The muzzle part 73 is thus movable in relation to thecollar 102. The collar 102 also has another property, which is that itcan be used for screwing in the muzzle part 73 at the barrel 68, andthis is possible as soon as the dice-formed part 107 with two oppositeflat surfaces is in contact with the corresponding surfaces 105 and 106of the flanges.

When the barrel 68 with the cartridge 63 in the chamber 69 is movedrearwards towards the cylindrical unit 16, the arm 60 will be moved intoan axial groove in the rear end of the barrel, so that the point 61 willsnap out in front of the front side surface of the flange 62. In thissituation the flange is in contact with the front cross surface of thecylindrical unit 16. When the barrel then, at the actuation of the grippart 139, is given a movement forwards, the cartridge 63 will beretained by the point 61, and the cartridge case will then fall out fromthe gun, or can be removed by hand.

1 claim:

1. Trigger mechanism for a cartridge tool with a releasing device with atransversally arranged spring actuated blocking member which is movablebetween a first axial position when the cartridge tool is off safety anda second axial position when the cartridge tool is on safetycharacterized in that a two-armed lever has a pivoting suspensionbetween its ends in the cartridge tool, the far end as seen in thelongitudinal direction of the cartridge tool displacing the blockingmember inwards at the first axial position, and the front end of thetwo-armed lever has a pivoting suspension at one end of an arm whichenters into a transverse hole in a trigger which is movable axially andis under spring pressure and connected to the trigger in such a way thatat a movement rearwards of the trigger against said pressure the far endof the two-armed lever will be dis placed toward the longitudinal axisof the cartridge tool and in that the under side of the two-armed leveris coacting with the opposite side surface of the hole in the trigger sothat at a movement forwards 0f the trigger said opposite surfaces givethe far end of the lever a movement away from the longitudinal axis ofthe cartridge tool.

2. Trigger mechanism according to claim 1, characterized in that saidfar end of the two-armed lever is provided with a lug with an obliquefront transverse surface, which is inclined forwards, and that saidblocking member has a lug for coaction with the firstmentioned lug,which has a rear transverse surface, which is inclined forwards viewedtoward the rear end of the cartridge tool, which two oblique surfacescoact with each other when the cartridge tool is actuated accidentally.

3. Trigger mechanism according to claim 1 characterized in that the amin the hole in the trigger has an arm section extending from it at anangle at the suspension point at the twoarmed lever, which arm sectionis movable in a groove in the two-armed lever and which arm section atits free end has an oblique surface coinciding with opposite obliquesurfaces at the end wall of the groove so that the movement of the armin the hole in the trigger is limited in the forwards direction of thecartridge tool.

1. Trigger mechanism for a cartridge tool with a releasing device with atransversally arranged spring-actuated blocking member which is movablebetween a first axial position when the cartridge tool is off safety anda second axial position when the cartridge tool is on safetycharacterized in that a two-armed lever has a pivoting suspensionbetween its ends in the cartridge tool, the far end as seen in thelongitudinal direction of the cartridge tool displacing the blockingmember inwards at the first axial position, and the front end of thetwo-armed lever has a pivoting suspension at one end of an arm whichenters into a transverse hole in a trigger which is movable axially andis under spring pressure and connected to the trigger in such a way thatat a movement rearwards of the trigger against said pressure the far endof the two-armed lever will be displaced toward the longitudinal axis ofthe cartridge tool and in that the under side of the two-armed lever iscoacting with the opposite side surface of the hole in the trigger sothat at a movement forwards of the trigger said opposite surfaces givethe far end of the lever a movement away from the longitudinal axis ofthe cartridge tool.
 2. Trigger mechanism according to claim 1,characterized in that said far end of the two-armed lever is providedwith a lug with an oblique front transverse surface, which is inclinedforwards, and that said blocking member has a lug for coaction with thefirst-mentioned lug, which has a rear transverse surface, which isinclined forwards viewed toward the rear end of the cartridge tool,which two oblique surfaces coact with each other when the cartridge toolis actuated accidentally.
 3. Trigger mechanism according to claim 1characterized in that the arm in the hole in the trigger has an armsection extending from it at an angle at the suspension point at thetwo-armed lever, which arm section is movable in a groove in thetwo-armed lever and which arm section at its free end has an obliquesurface coinciding with opposite oblique surfaces at the end wall of thegroove so that the movement of the arm in the hole in the trigger islimited in the forwards direction of the cartridge tool.